Boston Bruins' Matt Grzelcyk, right, celebrates with teammates including Kevan Miller (86) after scoring his first career goal during the second period of an NHL hockey game against the Pittsburgh Penguins in Boston, Friday, Nov. 24, 2017. The Bruins won 4-3. (AP Photo/Michael Dwyer)(Michael Dwyer)

BOSTON -- A veteran of the TD Garden "bull gang" for decades, Charlestown native John Grzelcyk plays a major role in the laborious operation that involves the arena's conversion from hockey rink to basketball court -- and vice-versa.

It's on a slightly smaller scale, but Grzelcyk is now going to have to make some interior alterations to his home, as well.

Atop the Grzelcyk's mantlepiece sits the puck that John's son, Matt, scored to lift Boston University to its 30th Beanpot championship in 2015 -- the overtime tally standing as one of John's proudest moments.

But now that puck is going to have share some space on the mantle -- with Matt Grzelcyk's first career NHL goal set to be featured, front and center.

John Grzelcyk has seen plenty of memorable goals at both Boston Garden and TD Garden over the years, but being in attendance for his son's goal Friday afternoon against the Pittsburgh Penguins easily stands at the top.

"It's going up there on the mantelpiece," John Grzelcyk said. "Probably up there with the goal he scored against Northeastern to win the Beanpot. It's right up there, the first NHL goal will be right up there. Now Bobby Orr's goal has moved down to three. It was (number) one, then he scored the Beanpot, so it went to two and now it's three.

For Matt -- who first skated out on the Garden ice when he was less than two years old -- lighting the lamp at a familiar venue was an experience he'll never forget.

"Yeah it was pretty special, obviously," Matt Grzelcyk said. "It brings back memories skating as a kid and stuff like that. It hasn't really set in yet, it was pretty cool to get that out of the way."

Aside from his individual accomplishment, Grzelcyk's goal was crucial in what was a 4-3 win for the Black and Gold Friday -- with the 23-year-old defenseman giving his team a two-goal cushion midway through the second period.

Grzelcyk reacted quickly to a broken play following a one-timer shot from David Krejci, as he quickly corralled the coasting puck and wristed it past Penguins goaltender Matt Murray for the score.

"Yeah it was kind of a jolt through my system," Grzelcyk said. "I didn't really know what was going on I was trying to hide it the best I could. I think the rest of the guys were trying to make me smile. I was really happy."

A recent call-up from Providence to help shore up Boston's injured defensive corps, Grzelcyk has impressed over his last two games -- tallying two points, three shots and averaging 14 minutes of ice time.

A undersized blue liner at 5-foot-9, Grzelcyk style of play bears some resemblance to fellow puck-moving defenseman Torey Krug, who noted that a faster NHL game has carved out a vital role for players like him and Grzelcyk.

"We don't have to worry too much, we have a playmaker on each pairing now and we can move the puck and it get it into the forwards hands and if you're breaking the puck out and you're not defending then you don't need to worry about the size of your guys out there," Krug said. "It's going to happen where we get hemmed into our own zone and we need to rely on our battle and our will to break those pucks out even more.

"I hope guys don't think of me as an under 5-foot-10 guy anymore, being a bigger part of the team you want to make sure guys aren't worried about things like that. Grzy will find his way, he played a heck of a game out there today."

Speaking after Friday's game, Matt was quick to note that his goal still hasn't quite sunk in.

Obviously, there's plenty of process -- and scores of messages to sort through on his phone.

"No I haven't," Grzelcyk said of looking at his phone. "I better make sure I have a charger before I check that."